Reactivity and regeneration of light hydrocarbon cracking catalyst

Catalytic performance of catalysts (H0108 and 1-P-H0108) for the catalytic cracking of light hydrocarbon was investigated in a fixed-bed plug-flow reactor under different reaction conditions. The yield of ethylene and propylene was enhanced and the formation of coke was restrained with the existence of water during the catalytic cracking process of light hydrocarbon. However, the stability of the catalyst was strongly affected by the water steam. TG/DTG results showed that there were two types of coke on the surface of the catalyst. The deactivated catalysts were almost completely regenerated by eliminating the coke at 750°C. The coking is the main cause of deactivation during the catalytic cracking without water. The activity of catalysts, which were deactivated in the presence of water, was partly retrieved by eliminating coke. In addition to the coking, the cause of deactivation in the presence of water is mainly due to the irreversible structural change of catalysts according to the temperature-programmed desorption of ammonia (NH₃-TPD) results.